The trait that Elizabeth and John Proctor share most fully through the first three acts of the play is that of pride. In the final act, they have both lost much of their connection to this particular trait.
Pride, fear, and shame kept Elizabeth from forgiving Proctor for the affair he had with Abigail. However, in the last act, after helping to condemn her husband to death with an ill-timed lie, Elizabeth appears humble. She refuses to attempt to convince Proctor of the proper course of action and instead tries to build him up and return to him a sense of goodness that she earlier helped to strip from him.
We see in her demeanor and in her words a new humility and deep sympathy. Proctor, for his part, is no longer truly connected to anyone. He has gone beyond relationships at this point and is engaged in a struggle for his soul - a fact which his dialogue acknowledges. He no longer strives for justice to be done, but works instead to find a way to live or die with some sense of integrity and honor.
This honor is not oriented by pride, as it was earlier in the play, but by a sense that honor comes from an understanding that one is responsible for one's own soul and one's own morality.
As Proctor wavers between the idea of confessing (to live) and the idea of dying, he debates the value of his actions, the value of his individuality and, symbolically, of his name. He is presented in this dilemma as being desperate and disturbed but, finally, strong.
He ends the play alone.